Insulating composition of matter



UUIVII'UOI I lunlo,

NG OR PLASTIC.

o Qt UNITED STATES L isa g PATENT OFFICE.

FRANK J. COOK, OF

CLEVELAND, OHIO.

INSULATING COMPOSITION OF MATTER.

No Drawing.

T 0 all whom it may concern:

Be it known that I, FRANK J. CooK, a citizen of the United States, residing at Cleveland, in the county of Cuyahoga and State of Ohio, have invented a certain new and useful Improvement in Insulating Composition of Matter, of which the following is a full, clear, and exact description.

The present invention relates to a composition of material which is a non-conductor of electricity, and is a poor conductor of heatso far as radiation of heat to the am? atmosphere is concerned, but does act as a conductor of heat between metals.

The composition of material has certain valuable properties, as will appear more fully as the description proceeds, which makes it eminently fitted for use as an insulating compositlon, in which electric resistance wire is embedded.

The composition of matter comprises as its ingredients pulverized soap-stone, or talc, pulverized feldspar, pulverized flint, and ball clay, all of which materials, as before stated, being in finely divided condition, are thoroughly mixed wlth each other and to the mixture there is added a suitable quantity of a solution of sodium silicate, which is preferably a 50% solution.

The proportions of the ingredients may be varied to meet varied requirements, but as a very satisfactory composition, I may state the following proportions:

Soapstone 10 parts Feldspar 1 part Flint 1 part Ball clay 1 part Solution sodium silicate to make de sired consistency.

The predominating ingredient is soapstone, and this ingredient supplies to t e composition the quality of absorbin heat and passing it on to a metal with whic it is in contact. The other ingredients enhance the baking and expanding properties of the composition as later explained.

The sodium silicate acts as a binder for the materials and while I prefer to use silicate of soda, other soluble silicates such as sodium silicate of potash may be used.

The quantit of silicate of soda solution added is sufficient to make a lastic mass or thick paste, in which conditlon the composition is ready for use When the compositlon has been placed Specification of Letters Patent.

Patented Oct. 11, 1921.

Application filed August 19, 1920. Serial No. 404,650.

and ormed for its ultimate use, the composition 1s ermitted to dr Y at a suitable temperature an 1n prac ice find a temperature of 200 F. is about right. After thorough (1m temperature is raised to approximately 250 F. at which temperature the baking mued until the composition is thoroughly baked and hardened, which requires approximately two hours although the baking time varies with the quantity and thickness of the material.

The composition of matter which has been described is particularly useful for use in connection with the laying of electric resistance wires u on a suitable support, and embedding suc wires to prevent rapid radiation of the heat to the atmosphere, and at the same time serving to hold the resistance wire in its laid position, thus maintaining the wires in the1r proper spaced relationship, and preventing them from moving from their fixed position.

When the resistance wire is applied so as to heat a metal body, as for instance an iron pipe or other metal structure, a thin coating of the material mixed as before stated is applied to the metal surface, thus filling in any irregularities in the surface, and this coating is driedout and baked as before stated. The resistance wire is then laid in place upon the coating, and a second coating 1s ap lied over the wires, forming a layer of suita le thickness and the article is again subjected to the drying and baking process.

If necessary, a third coating may be added, dried out and baked, as before stated. It will be understood that it is necessary and desirable that the electric resistance wire be completely embedded in the plastic material in order to prevent radiation to the air.

The composition of matter which has before been described has the peculiar property of conducting the heat from the electrical resistance wire, and passing it on to the metal with which it is in contact, but the radiation of heat through the described composition of matter from the electrical resistance wire to the atmosphere is very slow, particularly as compared with the radiation of heat to the metal object with which it is in contact. This property of the composition is very important, inasmuch as due to its plastic qualities when applied, it permits all the interstices in the surface of the metal to be filled, and when the wire is embedded in the plastic material, and subsequently baked, the heat from the wire when a current is passed throu h the same is evenly applied and distribute over all the metal surface with which the plastic n'iaterial is in contact.

The composition of matter when properly applied and baked has a degree of expansion, so that the composition expands with the heating of the metal to which it is applied and contracts with it when cooling, thus belingfree from cracking or blistering.

he material is highly resistant to the electric current, so that leakage of current between adjacent coils or parallel strips of the resistance wire or material is prevented.

\Vhere an electrical conductor, be it of resistance wire or a good conductor, is placed upon a porcelain support or support of refractory material, the composition which has been described may be employed to embed the Wire in the grooves of the porcelain insulator, in which event it is not necessary to apply a preliminary coating of the material, but simply apply a coating to the insulator after the wire is laid, baking the same, and

if necessary or desired, applying a second coat so as to completely embed the wires.

While the composition has been described with particular reference to its use in connection with electrical resistance wire, it will be understood that the use of it is not limited in this particular, but it is adaptable for use wherever its heat insulating and electrical insulating properties may be desired or advantageous.

Having described my invention, I claim 1. A composition of matter comprising substantially ten parts of pulverized soapstone, one part of feldspar, one part of flint, one-half part of ball clay, to which is added a binder.

2. A composition of matter comprising substantially ten parts of pulverized soapstone, one part of feldspar, one part of flint, one-half part of ball clay, and a binder consisting of sodium silicate.

In testimony whereof, I hereunto aflix my signature.

FRANK J. COOK. 

